You might want to watch part of the above video and then watch the entire video later on as you realize how many of these methodologies Obama is using. But if you can, especially try to watch the last few minutes, as it demonstrates the "because" factor that Obama uses quite effectively.

...and then read through this article below as much as you want. It's very credible. You may not want to start reading until page 27, as a lot of technical language and explanations are in the first few sections.

Oh - and I don't know for sure if the author writes about the gesture used by Obama when talking about Hilary during the primaries, but here's the clip in case you missed seeing it. I wouldn't have believed it, but I DO know what I see, and he indeed meant it. Most pundits dismiss it because they cannot imagine Obama consciously using this gesture (many younger people do this - it's not as though people wouldn't recognize it).

Personally I believe an explanation may be that Obama forgot that this gesture is already well known, and unthinkingly included it in his subliminal signals.